The present invention relates to a portable power machine, and more particularly to a portable power machine in which a working member is manipulated by a manipulation rod.
As a kind of the portable power machine mentioned above, there is a portable grass cutting machine, in which a cutter blade as the working member is supported at the front end of the manipulation rod and is driven by a motor disposed at the rear end of the manipulation rod. An operator uses an output manipulation member for controlling output of the motor to drive the cutter blade, and grips the manipulation rod by his/her hands to swing the cutter blade for grass cutting operation.
In the above-mentioned conventional grass cutting machine, the cutter blade will continue to rotate by inertia even if the operator manipulates the output manipulation member to stop the output of the motor imparted to the cutter blade when the operator wishes to stop the grass cutting operation. Therefore, it is considered to provide a brake member for stopping the working member quickly as the need arises and a brake manipulation member that can be manipulated by his/her hand for manipulating the brake member, so as to improve safety in grass cutting operation.
However, in this grass cutting machine, if the operator makes mistake in the sequential manipulation of the output manipulation member and the brake manipulation member, the machine can be damaged. For example, if the brake manipulation member is manipulated to stop the working member rapidly while maintaining the output of the power source imparted to the working member, the drive system and the brake system may be damaged by excessive stress, or energy loss may occur. A similar situation may occur if the output manipulation member is mismanipulated to increase output while holding the working member in a braked state.
In order to solve this problem, it is desirable to provide a mechanical relationship for working between the output manipulation member and the brake manipulation member, so that the brake manipulation member cannot be manipulated for brake operation before the output manipulation member is manipulated in the direction of stopping the output power to the cutter blade, and so that the output manipulation member cannot be manipulated for starting output to the cutter blade before the brake member is manipulated in the direction of releasing the brake operation.
However, since the grass cutting machine mentioned above is a portable type and the operator has to swing the manipulation rod of the machine for grass cutting operation, the overall structure of the machine should be compact along the longitudinal direction of the manipulation rod.